1. Field of the Invention
Embodiments of the present invention generally relate to methods of ultraviolet curing a substrate.
2. Description of the Related Art
Materials such as silicon oxide, silicon carbide and carbon-doped silicon oxide films find widespread use in the fabrication of semiconductor devices. One approach for forming such silicon-containing films on a substrate is through the process of chemical vapor deposition (CVD). Subsequent to formation of the CVD films, ultraviolet (UV) radiation can be used to cure and to densify the deposited films.
One manner of supplying UV radiation to a substrate uses UV radiation lamps. The bulbs used in UV lamp systems are consumable items with their life determined by a number of factors, including total hours of operation, number of starts, time in standby mode, power level, and other conditions. As UV bulbs near the end of their usable life, their output changes, thus affecting substrate-to-substrate processing uniformity. Additionally, UV bulbs within a chamber may not all be replaced simultaneously, thus, UV bulbs within the same lamp head may have different output levels. The non-uniform output within the chamber affects process uniformity across the processed substrates.
Thus, there is a need to improve the control of UV bulb output to increase process uniformity.